At this point, going to be seen monday and getting properly tested for yeast and bacterial infections vaginally is the next best step. don't try to self treat - be seen and get proper testing done.
even though you and your gf have protected sex, did you both get full std testing that included herpes testing prior to starting to have sex together? did you both have your gardasil shot series for hpv too?
grace
It could be an STI so go to your doctor I linked a website on what it sounds like but still get a check up
http://wiki.answers.com/Q/What_are_the_symptoms_of_chlamydia
the area tends to swell up, pains to walk.